(Hornik XXXXXXXXXXConsider σ(aT x + b), a ∈ A, b ∈ B. Extend Lemma 16.1 so that it holds for any Riemann integrable and non-polynomial sigmoid on some A containing a neighborhood of the origin, and on...

(Hornik (1993)). Consider σ(aT x + b), a ∈ A, b ∈ B. Extend Lemma 16.1 so that it holds for any Riemann integrable and non-polynomial sigmoid on some A containing a neighborhood of the origin, and on some nondegenerate compact interval B.